1. Technical Field
The present disclosure relates generally to apparatus and methods for accessing the interior of the body for performing surgery, diagnostics or other medical procedures. In particular, the present disclosure relates to an access assembly having an expandable anchor to secure and seal the access assembly to the patient's body.
2. Discussion of Related Art
Minimally invasive surgical procedures have recently been developed as alternatives to conventional open surgery. Minimally invasive procedures, such as laparoscopy, involve accessing the surgical area inside a patient through a plurality of ports introduced into the patient's body. This type of procedure is generally less traumatic to the body than open surgery, since these ports tend to cause less tissue damage and blood loss as compared to long incisions made for open surgery. A working space is typically created to provide space inside the surgical area for instruments to operate. For example, in laparoscopic surgery, the abdominal wall is elevated away from the organs in the body cavity. This is usually accomplished by filling the body cavity with a gas, such as carbon dioxide, raising the abdominal wall. This process, known as insufflation, is typically achieved by inserting a large-gauge needle known as a Veress needle into, for example, the intra-abdominal cavity for the introduction of gas. To perform surgical procedures in the intra-abdominal cavity, the insufflation pressure must be maintained, and the abdominal wall must remain elevated from the organs in the intra-abdominal cavity.
Once enlarged, the cavity may be accessed by inserting a trocar and cannula assembly through the abdominal wall. The trocar is a sharp stylet used to provide an initial penetration and access opening in the abdominal wall for the cannula. The trocar is removed and the cannula remains in the body to provide access to the surgical site.
In an alternative method known as the “open laparoscopy” method or the Hasson method, access is established to the peritoneal cavity through a small incision on the skin of the abdomen, typically through the umbilicus. A special open laparoscopic cannula is inserted. The physician uses standard laparotomy instruments and grasping forceps to laterally enlarge the initial incision and to lift/separate the fascia. This procedure eventually exposes the peritoneum and places it under tension so that it can be carefully pierced. Once accessed, the physician can pass a gloved finger into the cavity accessing the relevant anatomy and confirming safe entry. Upon securing access, the physician inserts the cannula through the incision and continues with a standard laparoscopic procedure.
During the surgical procedure, the pressurized integrity of the peritoneal cavity or pneumoperitoneum must be maintained even though there is substantial movement of the cannula during surgery. Unfortunately, it is often difficult to maintain a proper seal between the cannula and body tissue at the initial incision point. Prior art devices have typically employed a conical shaped sealing sleeve generally constructed from a rigid material. Upon insertion into the incision, the sleeve engages the tissue along the thickness of the incision and the sleeve's conical geometry pushes or displaces outward the tissue surrounding the incision. The tissue's natural resiliency will then cause the tissue to try to return to the tissue's original position which creates a sealing force against the surface of the sealing sleeve. The sleeve is usually sutured to the skin at a depth and position where the tissue's resiliency provides sufficient compression to maintain a seal. Another device maintains the integrity of the gas seal and anchors the cannula to the body using an inflatable membrane at the distal end of the cannula. A sealing member is pushed against the exterior side of the body, capturing tissue between the sealing member and the inflatable membrane.
It is also known to provide access for a surgeon to introduce his or her hand into the body during laparoscopic surgery. Such a hand access port should also be anchored to the patient's body, while providing a seal around the incision.
Accordingly, a need exists for apparatus and methods for anchoring a cannula or other access member to a patient with minimum tissue trauma while still providing a positive seal.